实验动物与出入境检验检疫

实验动物科学已成为现代科学技术的重要组成部分,是生命科学的基础和重要支撑条件.实验动物被广大科学工作者称为“活的试剂”、“活的精密仪器”,可以满足各种不同研究要求和生产需要,在诸多领域都有广泛的应用.随着生命科学的发展和经济全球化的深入,实验动物的应用领域更加广泛,相关产业和国际贸易与交流方兴未艾,并日臻成为出入境检验检疫工作的重要内容.本文对实验动物的应用现状、进出口情况、相关出入境检验检疫政策、面临的问题和相关建议等做一综述.     

与医科学生谈实验动物标准化

实验动物标准化由实验动物生产条件的标准化、实验动物质量标准化、动物实验条件的标准化以及与之相适应的饲养管理规范化和动物实验规范化几个部分组成。实验动物法制化管理是实验动物标准化的保证。动物实验是医学生物学必需的是实验手段之一,用标准的实验动物进行标准的动物实验是科研实验的基本要求。     

动物实验中的兽医作用

实验动物是现代医学研究中的重要基础和条件,随着我国实验动物科学的迅速发展和实验动物和动物实验质和量的不断提高,对实验动物兽医的需求越来越大,对实验动物兽医的要求和期望也越来越高,本文简要阐述了兽医在动物实验中的作用.文章就实验动物兽医应该具备的资质、实验动物兽医的基本职责以及实验动物健康与兽医管理等方面进行了讨论,明确了实验动物兽医的各项基本职责及任务.兽医在实验动物的管理以及动物实验的过程中有着非常重要的作用,在动物实验中应充分发挥兽医的作用.     

浅论实验动物兽医的职责及实践

随着我国实验动物科学和动物试验的迅速发展,实验动物兽医的需求越来越大。实验动物兽医的角色多种多样,广义地讲可以是任何具有兽医资质且从事实验动物管理、繁育、疾病诊断防治、动物试验和研究的人员。通常实验动物兽医是指实验动物临床兽医或实验动物主管兽医。实验动物兽医的天职是确保动物的健康和福利,并支持高质量的动物试验研究。本文从实验动物兽医工作的必要性、实验动物兽医的发展、实验动物兽医的资质、职责等几个方面,并结合合同外包研发机构中兽医的实践阐述了实验动物兽医的工作性质、任务和内容。     

实验动物许可证管理现状分析

随着生命科学研究的发展,我国实验动物科学进入快速发展时期,加强实验动物行业的规范化管理彰显重要。实验动物许可证管理是实验动物工作规范化、科学化管理的重要组成部分,同时也是推进实验动物学科发展的重要途径。随着国家实验动物立法和各省市对实验动物的配套立法等工作,促进了实验动物行业的有序发展,加强实验动物许可证的有效管理,对于促进我国实验动物的产业化和规范国家实验动物管理发挥了重要的推动与保障作用。本文对我国实验动物许可证管理现状进行分析,以对实验动物管理工作提供参考。     

军事医学科学院实验动物中心简介

军事医学科学院实验动物中心始建于1951年,是国内最早从事实验动物科学研究、生产繁育、动物实验及实验动物人才培训为一体的综合性实验动物专业单位。现设有实验动物生产、动物实验、饲料生产、科学研究等8个科室及实验动物微生物、遗传、病理、营养等专业学科,技术人员200多人。现有各种设施面积4万平方米,繁育供应各种实验动物20多种,年生产能力达60余万只。啮齿类动物生产全部达NPF标准。现有动物实验SPF级屏障设施5000平方米,设施条件国内领先,可承担各类动物实验课题。     

我国实验动物标准化及发展概况

实验动物科学是一门有关实验动物和动物实验的综合性新兴学科,始于50年代中期,由于它在生命科学中的重要地位,其发展迅速。本文拟对实验动物的标准化、新品系及模型动物的培育和应用、实验动物资源的开发和利用等实验动物科学主要发展方向略作介绍。1实验动物的标准化用标准的高质量的实验动物进行实验研究,能够排除动物本身影响实验结果的种种因素,得到准确、可靠、重复性好的实验结果。因此,实验动物的标准化具有重要意义。1.1实验动物标准化的发展趋势《实验动物管理条例》按微生物学控制标准,将我国实验动物分为四级,即一级动物(普通动…     

中国医学科学院医学生物学研究所医学灵长类中心

中国医学科学院医学生物学研究所医学灵长类中心,集实验动物饲养、繁殖、管理和实验动物科学研究、动物实验及实验动物人才培养等为一体的综合性实验动物研究基地,占地总面积约5．4万平方米,实验动物品种有猕猴,食蟹猴,树鼩,大、小鼠,家兔,豚鼠等。拥有一支从事实验动物和动物实验经验丰富的科研和技术队伍,也是中国医学科学院、北京协和医学院动物学硕士学位授予点,     

美国实验动物医学发展简史——对中国实验动物医学发展的思考

美国实验动物医学的发展起始于上世纪50年代,目前可能代表着世界上该领域的最高水平.本文对其发展史作了简的地回顾,包括生物医学领域对实验动物兽医的需求,实验动物科学领域早期的兽医实践,实验动物医学会的诞生,实验动物医学领域的培训、教育和考核等的沿革,以及相关法律法规对实验动物医学发展的影响等.笔者依据自身的工作实践和中国国情对中国实验动物医学领域的发展进行了一些思考,期盼实验动物相关法律法规能更加完善、在兽医教育中适度增加实验动物医学相关内容、加强实验动物医学领军人才的培养、加强实验动物医学界多渠道的交流、增加相关领域科研投入和支持等.中国要站在西方发达国家的肩膀上,借鉴其成功的经验,发展有中国特色的实验动物医学事业.     

中国医学科学院医学生物学研究所医学灵长类中心

中国医学科学院医学生物学研究所医学灵长类中心,集实验动物饲养、繁殖、管理和实验动物科学研究、动物实验及实验动物人才培养等为一体的综合性实验动物研究基地,占地总面积约5．4万平方米,实验动物品种有猕猴,食蟹猴,树鼩,大、小鼠,家兔,豚鼠等。     

The asymmetric distribution of the constituents of the Ran system is essential for transport into and out of the nucleus.

The GTPase Ran is essential for nuclear import of proteins with a classical nuclear localization signal (NLS). Ran''s nucleotide-bound state is determined by the chromatin-bound exchange factor RCC1 generating RanGTP in the nucleus and the cytoplasmic GTPase activating protein RanGAP1 depleting RanGTP from the cytoplasm. This predicts a steep RanGTP concentration gradient across the nuclear envelope. RanGTP binding to importin-beta has previously been shown to release importin-alpha from -beta during NLS import. We show that RanGTP also induces release of the M9 signal from the second identified import receptor, transportin. The role of RanGTP distribution is further studied using three methods to collapse the RanGTP gradient. Nuclear injection of either RanGAP1, the RanGTP binding protein RanBP1 or a Ran mutant that cannot stably bind GTP. These treatments block major export and import pathways across the nuclear envelope. Different export pathways exhibit distinct sensitivities to RanGTP depletion, but all are more readily inhibited than is import of either NLS or M9 proteins, indicating that the block of export is direct rather than a secondary consequence of import inhibition. Surprisingly, nuclear export of several substrates including importin-alpha and -beta, transportin, HIV Rev and tRNA appears to require nuclear RanGTP but may not require GTP hydrolysis by Ran, suggesting that the energy for their nuclear export is supplied by another source.     

Nuclear import of IkappaBalpha is accomplished by a ran-independent transport pathway

The inhibitor of kappa B alpha (IkappaBalpha) protein is able to shuttle between the cytoplasm and the nucleus. We have utilized a combination of in vivo and in vitro approaches to provide mechanistic insight into nucleocytoplasmic shuttling by IkappaBalpha. IkappaBalpha contains multiple functional domains that contribute to shuttling of IkappaBalpha between the cytoplasm and the nucleus. Nuclear import of IkappaBalpha is mediated by the central ankyrin repeat domain. Similar to previously described nuclear import pathways, nuclear import of IkappaBalpha is temperature and ATP dependent and is blocked by a dominant-negative mutant of importin beta. However, in contrast to classical nuclear import pathways, nuclear import of IkappaBalpha is independent of soluble cytosolic factors and is not blocked by the dominant-negative RanQ69L protein. Nuclear export of IkappaBalpha is mediated by an N-terminal nuclear export sequence. Nuclear export of IkappaBalpha requires the CRM1 nuclear export receptor and is blocked by the dominant-negative RanQ69L protein. Our results are consistent with a model in which nuclear import of IkappaBalpha is mediated through direct interactions with components of the nuclear pore complex, while nuclear export of IkappaBalpha is mediated via a CRM1-dependent pathway.     

Directed inhibition of nuclear import in cellular hypertrophy

Each nuclear pore is responsible for both nuclear import and export with a finite capacity for bidirectional transport across the nuclear envelope. It remains poorly understood how the nuclear transport pathway responds to increased demands for nucleocytoplasmic communication. A case in point is cellular hypertrophy in which increased amounts of genetic material need to be transported from the nucleus to the cytosol. Here, we report an adaptive down-regulation of nuclear import supporting such an increased demand for nuclear export. The induction of cardiac cell hypertrophy by phenylephrine or angiotensin II inhibited the nuclear translocation of H1 histones. The removal of hypertrophic stimuli reversed the hypertrophic phenotype and restored nuclear import. Moreover, the inhibition of nuclear export by leptomycin B rescued import. Hypertrophic reprogramming increased the intracellular GTP/GDP ratio and promoted the nuclear redistribution of the GTP-binding transport factor Ran, favoring export over import. Further, in hypertrophy, the reduced creatine kinase and adenylate kinase activities limited energy delivery to the nuclear pore. The reduction of activities was associated with the closure of the cytoplasmic phase of the nuclear pore preventing import at the translocation step. Thus, to overcome the limited capacity for nucleocytoplasmic transport, cells requiring increased nuclear export regulate the nuclear transport pathway by undergoing a metabolic and structural restriction of nuclear import.     

Histone deacetylase 4 possesses intrinsic nuclear import and export signals

Nucleocytoplasmic trafficking of histone deacetylase 4 (HDAC4) plays an important role in regulating its function, and binding of 14-3-3 proteins is necessary for its cytoplasmic retention. Here, we report the identification of nuclear import and export sequences of HDAC4. While its N-terminal 118 residues modulate the nuclear localization, residues 244 to 279 constitute an authentic, strong nuclear localization signal. Mutational analysis of this signal revealed that three arginine-lysine clusters are necessary for its nuclear import activity. As for nuclear export, leucine-rich sequences located in the middle part of HDAC4 do not function as nuclear export signals. By contrast, a hydrophobic motif (MXXLXVXV) located at the C-terminal end serves as a nuclear export signal that is necessary for cytoplasmic retention of HDAC4. This motif is required for CRM1-mediated nuclear export of HDAC4. Furthermore, binding of 14-3-3 proteins promotes cytoplasmic localization of HDAC4 by both inhibiting its nuclear import and stimulating its nuclear export. Unlike wild-type HDAC4, a point mutant with abrogated MEF2-binding ability remains cytoplasmic upon exogenous expression of MEF2C, supporting the notion that direct MEF2 binding targets HDAC4 to the nucleus. Therefore, HDAC4 possesses intrinsic nuclear import and export signals for its dynamic nucleocytoplasmic shuttling, and association with 14-3-3 and MEF2 proteins affects such shuttling and thus directs HDAC4 to the cytoplasm and the nucleus, respectively.     

我国实验动物科学带来的动物伦理及福利问题

实验动物是在一定条件下人工饲养繁殖,具有特定的生物学特性,用于科学研究的动物。实验动物是生命科学研究不可缺少的支撑条件,是为人类的健康和发展作出贡献和牺牲的生命体。实验动物科学包括实验动物和动物实验两个方面,是生命科学的重要分支。随着人类社会、经济和文化的发展,动物福利和动物伦理问题已经全面渗透到了实验动物科学乃至生命科学的各个领域之中。在我国,实验动物科学带来的伦理问题主要表现为：缺乏相应的法律法规,对虐杀实验动物的现象缺乏管理,违背实验动物伦理的技术操作现象依然存在,动物保护主义者和实验动物科学工作者之间的矛盾,等等。动物伦理学在中国出现的社会原因是：改革开放后经济的快速发展促使人们的观念转变,与国际的交往促进了东西方文化的交融,同时也是近十几年来教育的结果。近年来,我国实验动物科学领域内关于伦理问题和动物福利的研究进展迅速,实验动物纪念碑的出现和＂3R＂研究概念的传入是其主要表现。改善实验动物的生活条件,杜绝虐杀实验动物的现象,规范动物实验的技术操作,尽快制定和完善相关的法律法规,是进一步努力的目标;而落实组织措施,成立动物伦理委员会及专家组,加强与国际上的交流,推动＂3R＂研究的进展,扩大对社会的宣传,支持爱护动物的行为,注重与动物保护组织的理解及沟通等,是为达到这一目标应采取的措施。     

Analysis of the activity of nuclear export signals using fluorescent BSA conjugates

Here we demonstrate that fluorescein-labeled BSA conjugated with a mixture of nuclear import and export signals can be used to evaluate export activity. The method is based on the assumption that the intracellular distribution of the labeled conjugate [nuclear/cytoplasmic (N/C) fluorescent ratio] is dependent on the relative activity of the import versus the export signals. Using BALB/c cells as a model system, it was shown that this assumption is correct. Thus, the N/C fluorescent ratio increased significantly when an active leucine-rich nuclear export signal was replaced with its inactive mutant form in conjugates that also contained classical nuclear import signals. This approach was then used to demonstrate that the same leucine-rich nuclear export signal, which functions in vertebrates, is also active in amoebae.     

Protein export from the mitochondrial matrix

Assembly of a functional mitochondrion requires import of proteins from the cytosol and export of proteins from the matrix. Most previous studies have focused on the import pathway followed by nucleus-encoded proteins. However, it is now clear that proteins encoded in the nucleus as well as those encoded in the mitochondrion also move from the matrix into and across the inner membrane, a process defined here as export. These exported proteins are found in at least three cellular locations: the inner mitochondrial membrane, the intermembrane space and the cell surface. Here, we consider the pathways for export and the relationships between import and export.     

The carboxyl terminus of RNA helicase A contains a bidirectional nuclear transport domain

Human RNA helicase A was recently identified to be a shuttle protein which interacts with the constitutive transport element (CTE) of type D retroviruses. Here we show that a domain of 110 amino acids at the carboxyl terminus of helicase A is both necessary and sufficient for nuclear localization as well as rapid nuclear export of glutathione S-transferase fusion proteins. The import and export activities of this domain overlap but are separable by point mutations. This bidirectional nuclear transport domain (NTD) has no obvious sequence homology to previously identified nuclear import or export signals. However, the Ran-dependent nuclear import of NTD was efficiently competed by excess amounts of the nuclear localization signal (NLS) peptide from simian virus 40 large T antigen, suggesting that import is mediated by the classical NLS pathway. The nuclear export pathway accessed by NTD is insensitive to leptomycin B and thus is distinct from the leucine-rich nuclear export signal pathway mediated by CRM1.